Study Of Influencing Factors And Optimium Process Of The Ethanol Fermentation For Cellulose Ethanol Preparation From Apple Pomace

Cellulose ethanol is a kind of renewable clean energy in the world which is potential inapplication among alternatives to fossil energy. Fruit residues as non-food agriculturalbiomass are material for cellulosic ethanol production due to its rich component of cellulose.Apple pomace is a kind of fruit residues which is abundeant in domestic; therefore it is ofboth important significance and social benefits to research and develop the principle and thetechnology of ethanol production from apple pomace whether to improve the added value ofbiomass, or to alleviate the energy crisis. The main conclusions were as follows:1. Trichoderma reesei RUT-C30and UA8Aspergillus niger were used to saccharifyapple pomace which was pretreated with Trametes versicolor500202for different days,reducing sugar yield from saccharification and ethanol yield from fermentation were167.38g/Kg，180.66mL/Kg,respectively. Reducing sugar content and ethanol yield from pomacesaccharified with cellulase all exceeded that with compound fungi, but the difference betweenthem were less than10%.2. Reducing sugar content and ethanol yield increased with prolonging of pretreatmenydays in saccharification-fermentation with either cellulase or fungus treatment. The reducingsugar content showed a significant positive correlation with ethanol yield.3. Oscillations have a certain impact on the fermentation. Ethanol yield reached a peakafter6d fermentation under static culture while shaking culture reached the maximum after4d. It was derived that shaking shortened the fermentation duration.4. Immobilized yeast processing can improve the fermentation efficiency.Ethanol yieldfermented with free yeast reached to the fermentation peak after6d whereas that withimmobilized yeast reached to the maximum after4d, meanwhile the maximum withimmobilized yeast was higher than the free yeast maximum for11.51%.5. The impact of fermentation temperature, pH, inoculation dosage, and fermentationdays on ethanol yield all showed a ’bell curve’ law, so the four factors were optimized and thebest combination were obtained as follows: yeast inoculation dosage0.41%, fermentationtemperature34.34°C, pH4.53, fermentation time6.02d, and the ethanol yield reached to 205.21mL/Kg under these conditions.